U.S. patent application number 11/198026 was filed with the patent office on 2007-02-08 for methods for cementing using compositions containing salts.
This patent application is currently assigned to Halliburton Energy Services, Inc.. Invention is credited to Samuel J. Lewis, Michael J. Szymanski.
Application Number | 20070029089 11/198026 |
Document ID | / |
Family ID | 37716615 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070029089 |
Kind Code |
A1 |
Lewis; Samuel J. ; et
al. |
February 8, 2007 |
Methods for cementing using compositions containing salts
Abstract
Disulfonate salts of 2,4-pentanedione and methods for making
such salts are described. The disulfonate salts are useful as
cement dispersants. Cement compositions including such salts,
methods for making cement compositions including such salts, and
methods for performing cementing operations using such cement
compositions are also described.
Inventors: |
Lewis; Samuel J.; (Duncan,
OK) ; Szymanski; Michael J.; (Duncan, OK) |
Correspondence
Address: |
CRAIG W. RODDY;HALLIBURTON ENERGY SERVICES
P.O. BOX 1431
DUNCAN
OK
73536-0440
US
|
Assignee: |
Halliburton Energy Services,
Inc.
|
Family ID: |
37716615 |
Appl. No.: |
11/198026 |
Filed: |
August 5, 2005 |
Current U.S.
Class: |
166/293 ;
106/802; 106/809 |
Current CPC
Class: |
C09K 8/467 20130101;
C04B 2111/00017 20130101; C04B 24/16 20130101; C04B 2103/0079
20130101 |
Class at
Publication: |
166/293 ;
106/802; 106/809 |
International
Class: |
C04B 24/00 20060101
C04B024/00; E21B 33/13 20060101 E21B033/13 |
Claims
1. A method of cementing comprising: introducing a cement
composition comprising cementitious material, mixing fluid and a
disulfonate salt of 2,4-pentanedione into an area to be cemented;
and allowing the cement composition to set therein.
2. The method of claim 1 wherein the disulfonate salt of
2,4-pentanedione is selected from the group consisting of
2,4-pentanedione-1,5-sodium disulfonate;
2,4-pentanedione-1,5-potassium disulfonate;
2,4-pentanedione-1,5-magnesium disulfonate;
2,4-pentanedione-1,5-barium disulfonate;
2,4-pentanedione-1,5-ammonium disulfonate;
2,4-pentanedione-1,5-calcium disulfonate; and
2,4-pentanedione-1,5-cesium disulfonate.
3. The method of claim 1 wherein the cementitious material
comprises at least one of Portland cement, pozzolan cement, gypsum
cement, aluminous cement, silica cement, and alkaline cement.
4. The method of claim 3 wherein the cementitious material
comprises a Portland cement selected from the group consisting of
Classes A, B, C, G and H.
5. The method of claim 1 wherein the disulfonate salt of
2,4-pentanedione is present in an amount effective to reduce the
apparent viscosity of the cement composition as compared to a
cement composition where the disulfonate salt of 2,4-pentanedione
is not present.
6. The method of claim 1 wherein the disulfonate salt of
2,4-pentanedione is present in an amount selected from the group
consisting of from about 0.01% to about 5% by weight of the
cementitious material, from about 0.01% to about 4% by weight of
the cementitious material, and from about 0.01% to about 3% by
weight of the cementitious material.
7. The method of claim 1 wherein the mixing fluid comprises water
selected from the group consisting of fresh water, unsaturated salt
solution, brines, seawater, and saturated salt solution.
8. The method of claim 1 wherein the cement composition further
comprises at least one of a density modifying agent, dispersing
agent, retarding agent, accelerating agent, fluid loss control
strength retrogression control agent, defoaming agent, gas
migration agent, flow enhancing agent, surfactant or viscosifying
agent.
9. The method of claim 1 wherein the area to be cemented comprises
a subterranean zone.
10. The method of claim 1 wherein the area to be cemented comprises
an area subject to environmental regulations, and wherein the
disulfonate salt of 2,4-pentanedione has at least one of an
environmentally acceptable toxicity and a nationally acceptable
toxicity.
11. A method of cementing comprising: introducing a cement
composition comprising cementitious material, mixing fluid, and a
disulfonate salt of 2,4-pentanedione into a subterranean zone; and
allowing the cement composition to set therein; wherein the
disulfonate salt of 2,4-pentanedione has at least one of an
environmentally acceptable toxicity and a nationally acceptable
toxicity.
12. The method of claim 11 wherein the disulfonate salt of
2,4-pentanedione is selected from the group consisting of
2,4-pentanedione-1,5-sodium disulfonate;
2,4-pentanedione-1,5-potassium disulfonate;
2,4-pentanedione-1,5-magnesium disulfonate;
2,4-pentanedione-1,5-barium disulfonate;
2,4-pentanedione-1,5-ammonium disulfonate;
2,4-pentanedione-1,5-calcium disulfonate; and
2,4-pentanedione-1,5-cesium disulfonate.
13. The method of claim 1 wherein the cementitious material
comprises at least one of Portland cement, pozzolan cement, gypsum
cement, aluminous cement, silica cement, and alkaline cement.
14. The method of claim 11 wherein the disulfonate salt of
2,4-pentanedione is present in an amount effective to reduce the
apparent viscosity of the cement composition as compared to a
cement composition where the disulfonate salt of 2,4-pentanedione
is not present.
15. The method of claim 11 wherein the disulfonate salt of
2,4-pentanedione is present in an amount selected from the group
consisting of from about 0.01% to about 5% by weight of the
cementitious material, from about 0.01% to about 4% by weight of
the cementitious material, and from about 0.01% to about 3% by
weight of the cementitious material.
16. The method of claim 11 wherein the mixing fluid comprises water
selected from the group consisting of fresh water, unsaturated salt
solution, brines, seawater, and saturated salt solution.
17. The method of claim 11 wherein the cement composition further
comprises at least one of a density modifying agent, dispersing
agent, retarding agent, accelerating agent, fluid loss control
strength retrogression control agent, defoaming agent, gas
migration agent, flow enhancing agent, surfactant or viscosifying
agent.
Description
BACKGROUND
[0001] The present disclosure relates generally to salts that are
useful as cement dispersants, methods for making such salts, cement
compositions incorporating such salts, and methods for cementing
using cement compositions incorporating such salts. In particular,
a disulfonate salt of 2,4-pentanedione and methods for making and
using such a salt are described.
[0002] Cement dispersants are often used in cement compositions
utilized in construction for facilitating the mixing of the cement
compositions. Also, in the cementing of oil and gas wells and the
like, dispersants are extensively used to reduce the apparent
viscosities of the cement compositions utilized. The reduction of
the apparent viscosity of a cement composition allows the cement
composition to be pumped with less friction pressure and less pump
horsepower. In addition, the lower apparent viscosity often allows
the cement composition to be pumped in turbulent flow. Turbulent
flow characteristics are desirable when pumping cement compositions
in oil and gas wells to more efficiently remove drilling fluid from
surfaces in the well bore as the drilling fluid is displaced by the
cement composition being pumped. The inclusion of dispersants in
cement compositions is also desirable in that the presence of the
dispersants reduces the water required for preparation of the
cement compositions. Cement compositions having a reduced water
content are characterized by improved compressive strength
development.
[0003] A number of dispersing agents have been utilized heretofore
in cement compositions, particularly in cement compositions used
for primary and remedial cementing in oil and gas wells. For
example, certain organic acids, such as gluconic acid and citric
acid, have been used as cement dispersants. However, such organic
acids are also strong set retarding agents. That is, the presence
of an organic acid dispersant in a cement composition prevents the
cement composition from setting for a relatively long period of
time. Such a delayed set is often costly or otherwise detrimental.
Other dispersants that are commonly used in hydraulic cement
compositions include polynapthalene sulfonate, poly-B-naphthol
sulfonate, polymelamine sulfonate, and many others. While such
dispersants function very well in cement compositions, they can be
environmentally unacceptable, especially in offshore operations
where particular ecological properties may be required.
DESCRIPTION
[0004] According to embodiments described herein, a method of
cementing is provided. The method includes introducing a cement
composition comprising cementitious material, mixing fluid and a
disulfonate salt of 2,4-pentanedione into an area to be cemented,
and allowing the cement composition to set therein. In certain
embodiments, the 2,4-pentanedione disulfonate salt acts as a cement
dispersant. According to certain embodiments, the area to be
cemented is in a subterranean zone, which may be penetrated by a
well bore.
[0005] According to other embodiments described herein, methods of
preparing a disulfonate salt of 2,4-pentanedione are provided.
According to one such method, 2,4-pentanedione is sulfonated by
reacting it with a sulfur source, for example, chlorosulfonic acid.
The molar ratio of the sulfur source to 2,4-pentanedione is in the
range of from about 4:1 to about 1:1 in some embodiments, in the
range of from about 3:1 to about 2:1 in other embodiments, or in
the range of from about 3.5:1 to about 2.5:1 in still other
embodiments. The resulting product includes
2,4-pentanedione-1,5-disulfonic acid, and other acid by-products,
such as hydrochloric and sulfuric acids, and/or mono-sulfonic
acids.
[0006] The resulting product is then reacted with a base, for
example, sodium hydroxide, to neutralize the
2,4-pentanedione-1,5-disulfonic acid, thereby forming a salt of
2,4-pentanedione. The amount of base reacted with the resulting
product is that amount that will neutralize at least a portion of
the 2,4-pentanedione-1,5-disulfonic acid. In certain embodiments,
the base is added until the resulting product is neutralized to a
pH of about 7. Any other acids, such as hydrochloric, sulfuric, or
mono-sulfonic acids that may be present as by-products, may also be
neutralized by reaction with the base.
[0007] The neutralized product is then rinsed with a rinsing agent,
for example, methanol, to remove other acid by-products, such as
hydrochloric and sulfuric acids, and/or mono-sulfonic acids, and/or
to remove other salts formed by the neutralization, such as salts
of hydrochloric and sulfuric acids, and/or mono-sulfonic acids. It
was discovered that hydrophobic solvents, such as methanol, would
remove the by-product acids and/or salts, while leaving the salt of
2,4-pentanedione-1,5 disulfonic acid primarily undissolved.
[0008] According to other examples, the rinsing agent can be
another hydrophobic solvent such as ethanol, or can be a polar
solvent such as dimethylformamide ("DMF"), or can be any other
solvent that will remove or dissolve the by-products, and not the
disulfonate salt.
[0009] According to some exemplary methods for preparing a
disulfonate salt of 2,4-pentanedione, the reaction of
2,4-pentanedione with a sulfur source is conducted in an inert
solvent. The reaction solvent can be chloroform, or a halogenated
hydrocarbon such as carbon tetrachloride, 1,1,1-trichloroethane,
1,1,2-trichloroethane,1,1,1,2-tetrachloroethane and
1,1,2,2-tetrachloroethane.
[0010] According to other embodiments for preparing a disulfonate
salt of 2,4-pentanedione, the reaction of 2,4-pentanedione with a
sulfur source is conducted without a solvent. In still other
examples, the reaction occurs in an inert atmosphere. According to
one such example, the inert atmosphere comprises nitrogen.
[0011] According to some exemplary methods for preparing a
disulfonate salt of 2,4-pentanedione, the base that is reacted with
the reaction product of 2,4-pentanedione and a sulfur source
comprises an alkali metal or an alkaline earth metal. According to
one example of such methods, the base is sodium hydroxide, and the
neutralization reaction results in the formation of
2,4-pentanedione-1,5-sodium disulfonate, and may also result in
other salts from acid by-products that may have been present.
According to other embodiments, a potassium salt, a magnesium salt,
a barium salt, an ammonium salt, a calcium salt or a cesium salt of
2,4-pentanedione is prepared by reacting the reaction product of
2,4-pentanedione and a sulfur source with a base derived from
potassium, magnesium, barium, ammonium, calcium or cesium. Suitable
sources include but are not limited to hydroxides of potassium,
magnesium, barium, ammonium, calcium and cesium. The resulting
salts would include 2,4-pentanedione-1,5-potassium disulfonate;
2,4-pentanedione-1,5-magnesium disulfonate;
2,4-pentanedione-1,5-barium disulfonate;
2,4-pentanedione-1,5-ammonium disulfonate;
2,4-pentanedione-1,5-calcium disulfonate; and
2,4-pentanedione-1,5-cesium disulfonate, respectively.
[0012] According to still other embodiments, sulfonation of
2,4-pentanedione is achieved using oleum (fuming sulfuric acid)
which is commercially available from numerous sources including
DuPont. In still other alternative embodiments, sulfonation of
2,4-pentanedione is achieved using a falling film sulfur trioxide
sulfonation, equipment for which is commercially available from
sources such as Chemithon Corporation. In still other embodiments,
a 2,4-pentanedione-1,5-disulfonic acid is prepared as described in
U.S. Pat. No. 4,987,249 to Sandler, the entire disclosure of which
is hereby incorporated herein by reference, and is converted to the
salt by reaction with a base comprising an alkali metal or an
alkaline earth metal as described above. Exemplary bases include
but are not limited to sodium hydroxide, potassium hydroxide,
magnesium hydroxide, barium hydroxide, ammonium hydroxide, calcium
hydroxide and cesium hydroxide.
[0013] According to still other embodiments described herein, a
disulfonate salt of 2,4-pentanedione is provided. According to one
such embodiment, the salt comprises 2,4-pentanedione-1,5-sodium
disulfonate. According to another such embodiment, a disulfonate
salt of 2,4-pentanedione has an environmentally acceptable
toxicity. As used herein, the term "environmentally acceptable
toxicity" means that, when tested according to procedures that are
the same as or equivalent to those set forth by the OSPAR
Guidelines for Completing the Harmonised Offshore Chemical
Notification Format (HOCNF) (References number: 2003-1) that were
in effect on Dec. 31, 2004, the salt is determined to have a
toxicity of greater than about 10,000 mg/L for an algae
(skeletonema costatum), a crustacean (acartia tonsa), a fish
(scopthalmus) and a sediment reworker (corophium volutator).
[0014] OSPAR is a commission for protection of the marine
environment in the North-East Atlantic Sea. The HOCNF protocols in
effect on Dec. 31, 2004 are known to those of ordinary skill in the
art, and therefore need not be detailed herein. Generally, however,
the toxicity tests are conducted with a known number of organisms
(e.g., an algae, a crustacean, a fish, and a sediment reworker) in
a known amount of water. The test substance, which may be any of
the disulfonate salts of 2,4-pentanedione described herein, is
added to the water until the organisms die or become incapacitated.
The amount of 2,4-pentanedione disulfonate salt required to kill or
incapacitate half the test population is divided by the amount of
water to give mg/L.
[0015] According to yet another embodiment, a disulfonate salt of
2,4-pentanedione has a "nationally acceptable toxicity." As used
herein, the term "nationally acceptable toxicity" means that when
tested according to procedures that are the same as or equivalent
to those in effect in a country of interest on Dec. 31, 2004, the
salt is determined to have a toxicity acceptable for use in the
areas subject to such country's procedures.
[0016] According to one such embodiment, a disulfonate salt of
2,4-pentanedione has a nationally acceptable toxicity for the
United Kingdom. According to this embodiment, the salt would
qualify for a gold ranking under the chemical ranking scheme
employed in the United Kingdom on Dec. 31, 2004. This chemical
ranking scheme uses data established under the prescreening
criteria set by the Harmonised Mandatory Control System established
by OSPAR and the CHARM (Chemical Hazard Assessment and Risk
Management) algorithm to assign a hazard quotient to a chemical,
which quotient then correlates with a color on the following color
scale (from most acceptable to least acceptable): gold, silver,
white, blue, orange and purple.
[0017] According to another such embodiment, a disulfonate salt of
2,4-pentanedione has a nationally acceptable toxicity for Norway.
According to this embodiment, the salt would qualify for a yellow
ranking under the chemical ranking scheme employed in Norway on
Dec. 31, 2004. Under the Norway ranking scheme, a black ranking
indicates that the subject ingredient cannot be used in operations
in the Norwegian sector of the North Sea, a red ranking indicates
that the subject ingredient can only be used for a certain period
of time in the Norwegian sector of the North Sea, and a yellow
ranking indicates that the subject ingredient is acceptable for
most operations in the Norwegian sector of the North Sea. The
Norway ranking scheme also uses data established under the
Harmonised Mandatory Control System, for example the BODIS
(Biological Oxygen Demand of Insoluble Substance) and log P.sub.ow
(log of the octanol-water partition coefficient) values of the
subject ingredient. OSPAR, the Harmonised Mandatory Control System,
the CHARM algorithm, and the ranking schemes of OSPAR member
countries such as the United Kingdom and Norway, and techniques for
evaluating a chemical according to such systems and schemes, are
known to those of ordinary skill in the art.
[0018] A 2,4-pentanedione disulfonate salt as described herein has
a variety of uses, one of which is as an ingredient in cement
compositions. Thus, cement compositions comprising cementitious
material, mixing fluid and a disulfonate salt of 2,4-pentanedione
are described herein. Such cement compositions can include any of a
variety of cementitious materials, including but not limited to
hydraulic cements. Hydraulic cements set and harden by reaction
with water, and include Portland cements, pozzolan cements, gypsum
cements, aluminous cements, silica cements, and alkaline cements.
According to certain of the present embodiments, the cementitious
material comprises at least one API Portland cement. As used
herein, the term "API Portland cement" means any cement of the type
defined and described in API Specification 10, 5th Edition, Jul. 1,
1990, of the American Petroleum Institute, which includes Classes
A, B, C, G, and H. According to certain examples disclosed herein,
the cementitious material comprises any of Classes G and H cement.
The preferred amount of cementitious material is understandably
dependent on the cementing operation.
[0019] According to certain embodiments, the 2,4-pentanedione
disulfonate salt included in a cement composition is selected from
the group consisting of 2,4-pentanedione-1,5-sodium disulfonate;
2,4-pentanedione-1,5-potassium disulfonate;
2,4-pentanedione-1,5-magnesium disulfonate;
2,4-pentanedione-1,5-barium disulfonate;
2,4-pentanedione-1,5-ammonium disulfonate;
2,4-pentanedione-1,5-calcium disulfonate; and
2,4-pentanedione-1,5-cesium disulfonate.
[0020] The 2,4-pentanedione disulfonate salt can be mixed with the
cementitious material as a dry ingredient, or can be mixed with the
cementitious material as a solution. The amount of 2,4-pentanedione
disulfonate salt to include in a cement composition depends upon
the application to be made with the cement composition. However,
according to one embodiment, a disulfonate salt of 2,4-pentanedione
is present in a cement composition in an amount effective to reduce
the apparent viscosity of the cement composition. Thus, a
disulfonate salt of 2,4-pentanedione as described herein is
suitable for use as a dispersant. According to other embodiments, a
disulfonate salt of 2,4-pentanedione is present in a cement
composition in an amount of from about 0.01% to about 5% by weight
of the cementitious material. According to still other embodiments,
a disulfonate salt of 2,4-pentanedione is present in a cement
composition in an amount of from about 0.1% to about 4% or from
about 0.1% to about 3% by weight of the cementitious material in
the composition.
[0021] According to certain examples of cement compositions
illustrated herein, the mixing fluid comprises water. Preferably,
the water is present in an amount sufficient to make a slurry of a
desired density from a mix comprising cementitious material and a
disulfonate salt of 2,4-pentanedione. The water used to form a
slurry can be fresh water, unsaturated salt solution, including
brines and seawater, and saturated salt solution. Generally, any
type of water can be used, provided that it does not contain an
excess of compounds known to those of ordinary skill in the art to
adversely affect properties of the cement composition. According to
one embodiment, the water is present in an amount of about 20% to
about 200% by weight of the cementitious material. According to
other embodiments, water is present in an amount of from about 25%
to about 150%, about 30% to about 100%, or about 30% to about 70%
by weight of the cementitious material.
[0022] According to still other exemplary cement compositions, any
of a variety of additives known to those of ordinary skill in the
art may be included. Such additives may include density modifying
materials (e.g., silica flour, sodium silicate, microfine sand,
iron oxides and manganese oxides), dispersing agents, retarding
agents, accelerating agents, fluid loss control agents, strength
retrogression control agents, defoaming agents, gas migration
agents, flow enhancing agents, surfactants, and viscosifying
agents.
[0023] The following examples are illustrative of the foregoing
methods and compositions.
EXAMPLE 1
[0024] A disulfonate salt of 2,4-pentanedione was prepared by first
adding 575.7 ml (1009.2 g, 8.66 mol) of chlorosulfonic acid to
about 1 L of chloroform in a 3 L round bottom flask equipped with a
nitrogen adapter to maintain an inert atmosphere, a water condenser
(to minimize chloroform evaporation), and another nitrogen adapter
to vent liberated gases.
[0025] The resulting solution was cooled to 0.degree. C., and 403.8
ml (393.7 g, 3.93 mol) of 2,4-pentanedione was slowly added via a
pressure-equalized slow addition funnel. The solution was stirred
and maintained at 0.degree. C. throughout the addition process.
After completing the addition of the 2,4-pentanedione, the
temperature of the solution was raised to 60.degree. C., and the
solution was stirred overnight.
[0026] During the temperature increase, hydrochloric acid was
liberated and was vented into a fume hood. After the hydrochloric
acid evolution ceased, the reaction mixture was stirred while
slowly cooling to room temperature. The resulting dark red viscous
liquid was quenched with about 1 L of water and separated from the
chloroform via a separatory funnel to result in an acid product
that included 2,4-pentanedione-1,5-disulfonic acid, hydrochloric
and sulfuric acids. The acid product was then neutralized to a pH
of about 7, which resulted in the formation of
2,4-pentanedione-1,5-sodium disulfonate. The neutralization was
performed by slowly adding 314.4 grams (about 2 molar equivalents
of the 2,4-pentanedione-1,5-disulfonic acid ) of sodium hydroxide
under atmospheric conditions. The reaction is extremely exothermic,
therefore the sodium hydroxide was added slowly so that atmospheric
conditions could be maintained. The hydrochloric and sulfuric acid
by-products can be neutralized into NaCl (from the hydrochloric
acid) and Na.sub.2SO.sub.4 (from the sulfuric acid) with additional
sodium hydroxide.
[0027] The neutralized product was then rinsed several times with
methanol to remove by-product acids, or any salts formed therefrom,
while leaving the 2,4-pentanedione-1,5-sodium disulfonate primarily
undissolved. When compared to the 2,4-pentanedione-1,5-disulfonic
free acid, the 2,4-pentanedione-1,5-disulfonic salt was
significantly less soluble, which was unexpected because with many
substances, like aromatic salts, the salt is more soluble than the
free acid. The rinsed product was dried in a vacuum oven and
filtered through a 300 mesh screen to afford a flowing pale
orange/red powder. The resulting powder was
2,4-pentanedione-1,5-sodium disulfonate.
[0028] The particular amounts recited in this Example 1 are
illustrative only, as amounts other than those recited above can be
used to render molar ratios of reaction and/or neutralization
ingredients suitable for preparing a disulfonate salt of
2,4-pentanedione as disclosed herein.
EXAMPLE 2
[0029] Example 2 illustrates an exemplary use for a
2,4-pentanedione disulfonate salt. While the salt has other
utilities, this Example 2 illustrates use of the salt as a
dispersant in cement compositions.
[0030] Sixteen cement compositions (Composition Nos. 1-16) and
certain properties of such compositions are described in Table 1.
Each of the compositions was prepared from a base of 100%
cementitious material. The cementitious material for Composition
Nos. 1-12 and 15-16 was API Class G cement obtained from Dyckerhoff
AG. The cementitious material for Composition No. 13 was API Class
H cement obtained from LaFarge Corp.'s Joppa plant in Illinois. The
cementitious material for Composition No. 14 was API Class H cement
obtained from Texas Industries, Inc. ("TXI").
[0031] A dispersant and other additives (where indicated) were
added to the base of each cement composition (i.e., to the
cementitious material) in the amounts reported in Table 1, where "%
bwoc" indicates a weight percentage by total weight of the
cementitious material.
[0032] Dispersant Type A used for Composition Nos. 1, 5, 7, 10, 11
and 13-16 comprised a disulfonate salt of 2,4-pentanedione as a
dispersant. The 2,4-pentanedione disulfonate salt used for the
compositions of Example 2 was 2,4-pentanedione-1,5 sodium
disulfonate prepared according to Example 1, however, a
2,4-pentanedione disulfonate salt can be obtained by other methods
as discussed herein.
[0033] Dispersant Type B used for Composition Nos. 2, 6 and 8
comprised a condensation product of formaldehyde, acetone and a
sulfite, which is a known dispersant commercially available under
the tradename CFR-3.TM. from Halliburton Energy Services, Duncan,
Okla.
[0034] Dispersant Type C used for Composition Nos. 3 and 9
comprised a phenolic hydroxyl group blocked alkali metal
lignosulfonate, which is a known dispersant commercially available
under the tradename CFR-5.TM. from Halliburton Energy Services,
Duncan, Okla.
[0035] Composition Nos. 4 and 12 did not include a dispersant.
[0036] Other Additive Type D, used for Composition Nos. 1-3,
comprised a grafted lignin as a retarder, which is commercially
available under the tradename FDP601.TM. from Halliburton Energy
Services, Duncan, Okla.
[0037] Other Additive Type E indicates a group of additives, each
available from Halliburton Energy Services, Duncan, Okla., that
were used to form Composition Nos. 7-9. The additives indicated by
Type E according to the embodiments illustrated by Composition Nos.
7-9 comprised: 0.5% bwoc of a gas migration agent comprising
silica, which is available under the tradename Gascon.TM.; 1.1%
bwoc of a retarder comprising a refined lignosulfate, which is
available under the tradename HR-5L.TM.; 0.2% bwoc of a defoaming
agent comprising a seed oil and surfactants, which is available
under the tradename NF-6.TM.; 0.1% bwoc of a flow enhancing agent
comprising a silica supported acid, which is commercially available
under the tradename EZFlo.TM.; 5.5% bwoc of a fluid loss agent
comprising a cellulose, which is commercially available under the
tradename Halad 613.TM.; and 2.2% bwoc of a fluid loss agent
comprising a grafted acrylic polymer, which is commercially
available under the tradename Halad 600.TM.. Each additive in the
group of additives indicated by the designation "E" was mixed with
the cement, dispersant, and mixing fluid to form Composition Nos.
10-12.
[0038] Other Additive Type F, used for Composition Nos. 10-11,
comprised a refined lignosulfonate, which is commercially available
as a retarder under the tradename HR-5 from Halliburton Energy
Services, Duncan, Okla.
[0039] The procedure followed for preparing each cement composition
with the cementitious materials, dispersant, additives and mixing
fluid as described above was API Specification RP 10B, 22nd
Edition, 1997, of the American Petroleum Institute, which is a
specification known to those of ordinary skill in the art.
Generally, according to said specification, the cementitious
material, dispersant and other additive (where applicable) were
dry-blended (the "dry blend") and then added over a 15 second
period to mixing fluid being maintained in a blender at 4000 RPM.
When all of the dry blend was added to the mixing fluid, a cover
was placed on the blender and mixing was continued at about 12,000
RPM for about 35 seconds. For each cement composition, the mixing
fluid comprised water in the amount as listed in Table 1, where "%
bwoc" indicates a weight percentage by total weight of the
cementitious material. The density (lb/gal) of each composition is
reported in Table 1.
[0040] The plastic viscosity ("PV"), yield point ("YP") and
thickening time ("TT") were also tested for the compositions
indicated in Table 1, at the test temperatures indicated in Table
1. Each of the plastic viscosity, yield point and thickening time
was tested (where indicated) according to procedures well known to
those of ordinary skill in the art, and which are described in API
Specification RP 10B, 22nd Edition, 1997, of the American Petroleum
Institute. In Table 1, the results of the PV tests are reported in
centipoises and the results of the YP tests are reported in
Pascals. The results of the TT tests are reported in time
(hours:minutes) that it took the composition to attain 100 Bearden
units of consistency (BC) in a high pressure consistometer,
determined as described in API Specification RP 10B referenced
above. TABLE-US-00001 TABLE 1 Other Dispersant Additive Mixing Type
and Type and Test Fluid Amount Amount Density Temp PV YP TT No. (%
bwoc) (% bwoc) (% bwoc) (lb/gal) (.degree. F.) (cp) (Pascal)
Hrs:Mins 1 35 A D 16.92 80 96 8.2 not tested 0.2 0.1 2 35 B D 16.92
80 89 1 not tested 0.2 0.1 3 35 C D 16.92 80 127.4 7.4 not tested
0.2 0.1 4 41.80 none none 16.14 80 55 11 3:28 5 41.80 A none 16.10
80 31 6 5:19 0.684 6 41.80 B none 16.10 80 settle settle 8:38 0.684
7 41.80 A E 14.99 122 35.6 2 5:15 0.684 8 41.80 B E 14.99 122 45.4
0 7:30 0.684 9 41.80 C E 14.99 122 46.7 0 9:07 0.684 10 41.80 A F
16.09 122 34.9 9.8 3:02 0.684 0.15 11 41.80 A F 16.09 122 27.8 11.3
2:50 0.684 0.11 12 41.80 none none 16.14 122 not not tested 2:01
tested 13 32 A none 17.31 80 44.8 5.9 not tested 0.45 14 29 A none
17.75 80 200 10 not tested 0.50 15 41.80 A none 16.10 122 65 16.9
2:38 0.684 16 41.80 A none 16.10 122 66.4 11.8 2:29 0.684
[0041] Those of ordinary skill in the art understand that the
presence of a dispersant in a cement composition affects the PV of
the composition, as well as the YP. PV and YP indicate rheological
properties of a cement composition, where PV is related to the
mechanical friction between particles and YP is related to the
force required to break interactive bonds between particles and
then to produce movement. In any given application, it may be
desirable to increase or decrease the PV or the YP of a cement
composition to achieve rheological properties suitable for that
application. Those of ordinary skill in the art understand that a
desirable value for either PV or YP depends on the application (for
example, the type of cementing being performed and the conditions
under which the cementing will occur) being made with the cement
composition. Generally, however, those of ordinary skill in the art
understand that the thickness of a cement composition varies in
direct relationship to the PV value of the cement composition.
Cement compositions that are too thick for a given application have
flowability problems. Thus, a desirable PV for a cement composition
is one that, for a given application, is low enough to avoid
flowability problems, but high enough to provide the cement
composition with the desired rheological property for the given
application. As to YP, those of ordinary skill in the art
understand that, generally, the lower the YP of cement composition,
the more likely it is that the constituents of the composition will
settle out. Thus, a desirable YP is one that is high enough to
prevent settling, but low enough to provide the cement composition
with the desired rheological property for the given
application.
[0042] Considering that a desirable value for either PV or YP
depends on the application being made with the cement composition,
the PV and YP data for Composition Nos. 1, 5, 7, 10, 11 and 13-16
illustrate that cement compositions that include a dispersant
comprising a disulfonate salt of 2,4-pentanedione exhibit favorable
rheological properties as compared to cement compositions
comprising conventional dispersants (i.e., Composition Nos. 2, 3,
6, 8 and 9.)
[0043] In particular, a comparison between Composition Nos. 1-3,
each of which comprised a different Dispersant Type, in equal
amounts respectively, and the same Other Additive Type amount, in
equal amounts, shows that Composition No. 1 (which comprised a
disulfonate salt of 2,4-pentanedione and Additive Type D) has a PV
value less than that of Composition No. 3 (which comprised
CFR-5.TM. dispersant and Additive Type D), but a YP value greater
than that of No. 3, thus making Composition No. 1 a more suitable
cement composition for certain applications. As between Composition
No. 2 (which comprised CFR-3.TM. dispersant and Additive Type D)
and Composition No. 1, Composition No. 1 has a greater PV and
larger YP value, thus making Composition No. 1 a more suitable
cement composition for certain applications.
[0044] Composition No. 4, which included only water and cement,
provides a control for comparison of compositions that included
water, cement, and one of Dispersant Types A, B and C, such as
Compositions Nos. 5 and 6. For example, a comparison between the
PV, YP and TT values of Composition Nos. 4, 5 and 6 illustrates
that cement compositions that include a disulfonate salt of
2,4-pentanedione (Dispersant Type A) have rheological properties
and thickening times that make them more suitable for certain
applications than cement compositions that do not include a
disulfonate salt of 2,4-pentanedione (Composition No. 4), or that
include a different Dispersant Type (Composition No. 6).
[0045] Further, Composition Nos. 5 and 6 are useful for comparing
cement compositions that include, respectively, a disulfonate salt
of 2,4-pentanedione as a dispersant (Dispersant Type A) and a
conventional dispersing agent (Dispersant Type B), in equal
amounts. The PV and YP data indicate that Composition No. 5 did not
settle, while Composition No. 6 did. Those of ordinary skill in the
art understand that settling is an undesirable occurrence for a
cement composition. Thus, the PV and YP data indicate that a
dispersant comprising a disulfonate salt of 2,4-pentanedione
(Dispersant Type A) contributes favorable Theological properties to
a cement composition. Moreover, the TT of Composition No. 5 was
approximately 3 hours less than that of Composition No. 6. A
shorter TT is desirable in certain cement applications, thus making
a cement composition such as Composition No. 5 more suitable for
certain applications.
[0046] Composition Nos. 7-9 illustrate compositions comprising the
same type and amount of Other Additive (Type E), but equal amounts
of different Dispersant Types. The PV and YP data indicate that
Composition No. 8 (which comprised CFR-3.TM. dispersant and
Additive Type E) exhibits PV and YP properties substantially
similar to that of Composition No. 9 (which comprised CFR-5.TM.
dispersant and Additive Type E). Composition No. 7, however, (which
comprised a disulfonate salt of 2,4-pentanedione and Additive Type
E) has a lower PV value, but a larger YP value, thus making
Composition No. 7 more suitable than Composition Nos. 8 and 9 for
certain applications. Moreover, the TT of Composition No. 7 was
shorter than that of Composition Nos. 8 and 9, which makes a cement
composition such as Composition No. 7 more suitable for
applications where it is desirable to have a shorter TT.
[0047] Composition Nos. 10-11 illustrate compositions comprising
equal amounts of Dispersant Type A (a disulfonate salt of
2,4-pentanedione), but different amounts of Other Additive Type F
(a refined lignosulfonate retarder). Composition Nos. 10 and 11
illustrate that conventional retarders, such as Type F, are
effective in cement compositions comprising a salt of
2,4-pentanedione. Such cement compositions achieve favorable
rheological properties as indicated by the reported YP and PV
values, and the retarder still functions to slow the TT's of such
compositions.
[0048] Thus, the TT's of cement compositions that include a
disulfonate salt of 2,4-pentanedione can be adjusted with
conventional retarders. In any given application, it may be
desirable to have a longer or shorter TT. The TT of Composition No.
12, which included only water and cement, provides a control for
comparison of compositions that included Dispersant Type A, and
optionally, retarding agents. For example, the TT of Composition
Nos. 10 and 11 (each of which included a retarding agent) is longer
than that of Composition No. 12. The TT of Composition Nos. 15 and
16 (each of which did not include a retarding agent) is also longer
than that of Composition No. 12, although not as long as
Composition Nos. 10 and 11.
[0049] Composition Nos. 13-16 illustrate compositions that include
a disulfonate salt of 2,4-pentanedione as a dispersant in varying
amounts. The PV and YP data for each of these compositions
illustrate that the disulfonate 2,4-pentanedione salt is an
effective dispersant in varying amounts over a broad temperature
range. The amount of a disulfonate salt of 2,4-pentanedione to
include in a cement composition as a dispersant according to the
present embodiments depends upon the application to be made with
the cement composition. However, according to one embodiment, a
dispersant comprising a disulfonate salt of 2,4-pentanedione is
present in a cement composition in an amount effective to reduce
the apparent viscosity of the cement composition.
EXAMPLE 3
[0050] Example 3 illustrates an exemplary use for a
2,4-pentanedione disulfonate salt as an ingredient in cement
compositions required to comprise ingredients meeting an
environmentally acceptable toxicity or a nationally acceptable
toxicity. A 2,4-pentadionedione disulfonate salt as described
herein was determined to have an environmentally acceptable
toxicity and a nationally acceptable toxicity. In particular,
2,4-pentanedione-1,5-sodium disulfonate prepared according to
Example 1 was determined to have a toxicity of greater than about
10,000 mg/L for an algae (skeletonema costatum), a crustacean
(acartia tonsa), a fish (scopthalmus) and a sediment reworker
(corophium volutator).
[0051] In this Example 3, the toxicity results for the skeletonema
costatum were determined according to ISO (International
Organization for Standardization) 10253, the protocol for which is
known to those of ordinary skill in the art, and is also the
protocol required under the above-referenced HOCNF Guidelines. The
toxicity results for the acartia tonsa were determined according to
ISO 14669, the protocol for which is known to those of ordinary
skill in the art. The toxicity results for the scopthalmus and the
corophium volutator were determined according to Part B of the
OSPAR Protocols on Methods for the Testing of Chemicals Used in the
Offshore Industry (published by OSPAR in 1995).
[0052] A toxicity result of greater than about 10,000 mg/L for the
species tested in this Example 3 indicates that
2,4-pentanedione-1,5-sodium disulfonate has a low toxicity such
that it would have an environmentally acceptable toxicity and/or a
nationally acceptable toxicity in at least one country of interest,
for example the United Kingdom or Norway. Such toxicity
acceptability makes 2,4-pentanedione-1,5-sodium disulfonate
particularly useful for compositions required to meet a particular
environmental standard. Other 2,4-pentanedione disulfonate salts as
described herein should also have low toxicity such that they would
have an environmentally acceptable toxicity and/or a nationally
acceptable toxicity in at least one country of interest.
[0053] Other embodiments of the current invention will be apparent
to those skilled in the art from a consideration of this
specification or practice of the invention disclosed herein.
However, the foregoing specification is considered merely exemplary
of the current invention with the true scope and spirit of the
invention being indicated by the following claims.
* * * * *